Railway switch operating apparatus



Nov. 9, 1937. K. J. J. M GOWAN 2,098,331

RAILWAY SWITCH OPERATING APPARATUS Filed March 29, 1935 4 Sheets-Sheet INVENTOR HIS ATTORNEY Nov. 9, 1937.

K. J. J. MCGOWAN RAILWAY SWITCH OFERATING APPARATUS 4 Sheets-Sheet 2 Filed March 29, 1935 BY HIS ATTORNEY Nov. 9, 1937. K. J. J. McGOWAN 2,098,831

RAILWAY SWITCH OPERATING APPARATUS Filed March 29, 1935 4 sheets-sheets INVENTOR HIS ATTORNEY BY Clam/IQ Nov. 9, 1937. K. J. J. M GOWAN RAILWAY SWITCH OPERATING APPARATUS Filed March 29, 1935 4 SheetsSheet 4 INVENTOR JJMG0waI2 H IS ATTORNEY Patented Nov. 9, 1937 UNETED STATES PATENT GFFECE' RAILWAY SWITCH OPERATING APPARATUS Application March 29, 1935, Serial No. 13,682

9 Claims.

My invention relates to railway switch operating apparatus.

One object of my invention is to provide means for biasing the movable rails of a switch to a selected extreme position in such manner that when a train trails the switch and displaces the movable rails from the selected extreme position, the biasing means will become effective to urge the movable rails to their opposite extreme position for a time interval which is preferably sufficiently long to permit the train to completely trail the switch, whereupon the biasing means will again become effective to bias the movable rails to their original positions.

Other objects of my invention will appear as the description proceeds.

I will describe one form of apparatus embodying my invention, and. will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. l is a top plan view showing a railway switch A provided with one form of switch operating apparatus embodying my invention. Fig. 2 isan enlarged top plan view, with the cover removed, of. the biasing mechanism C forming part of the apparatus iilustrated in Fig. l, the parts being shown in their normal positions. Fig. 3 is a vertical longitudinal sectional view of the device C shown in Fig. 2 with certain of the parts removed to better illustrate the construction of the remaining parts. Fig. 4 is a transverse sectional view of the mechanism) shown in Fig. 2 taken substantially on the line IV-IV of Fig. 2. Fig. 5 is a top plan view of the mechanism shown in Fig. 2 with the cover and a number of the operating parts removed. Fig. 6 is an end View of the spring unit U forming part of the biasing mechanism shown in the preceding views. Fig. '7 is a top plan view showing certain of the parts of the mechanism C illustrated in Fig. 2 removed from the mechanism, these parts being in the relative positions in which they are shown in Fig. 2. Fig. 8 is a side view of the latch th and link w as they appear when viewed from the left in Fig. '7. Fig. 9 is a side view of the selector lever it and floating lever Il asthey appear when viewed from below in Fig. 2. Fig. 10 is a vertical sectional view of the roller assembly R forming part of the biasing mechanism C shown in Fig. 2. Fig. 11 is a view similar to Fig. 2, but showing the parts in the positions which they occupy when the switch is moved from its normal position to its reverse position by a trailing train.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Fig. 1, the reference charac ter A designates a railway switch comprising, as usual, two fixed rails l and l and two movable rails or switch points 2 and 2 the switch points being connected together adjacent their tips by 5 a front rod 3 and a composite head rod 4.

Associated with the switch A is a switch operating device B which may be of any suitable type, but which in the form here shown comprises a switch stand 5 having its base 5 spiked or 10 otherwise secured to the ties adjacent the switch A. A gear shaft 6 is journaled in the switch stand 5, and carries a crank l and a gear segment 8. The gear segment 8 meshes with a pinion gear Q keyed to a pinion shaft ill. The pinion 15 shaft it extends through the side of the switch stand 5, and has attached to its outer end the usual weighted switch-throwing lever l 8.

Also associated with the switch A is a biasing mechanism 0 embodying my present invention. As here shown, this mechanism comprises a suitable casing I2 provided with a removable cover l3. The casing I2 is bolted to the head rod 4 to move therewith, and is provided at its opposite ends with aligned guideways l2 which slidably receive an operating rod l4, one end of which is operatively connected with the previously mentioned crank l. of the switch stand 5 by means of a connecting rod l5. Formed in one side of the operating rod within the casing I2 are two notches M and li separated by a recess I4 The notch M cooperates with a selector lever l6 (see Fig. 2) while the notch M cooperates with a selector lever I6 As best seen in Figs. '7 and 9, the selector lever it is a casting or forging having a horizontally disposed substantially L-shaped lower portion a the long leg I) of which terminates at the end opposite to the short leg 0 in an upright extension d. The lower portion a of the selector lever is 40 provided at the junction of the long and short legs with a depending cam follower e, while the upright extension 02 is provided with two laterally projecting, vertically spaced, apertured lugs 7 and g, and with an upstanding lug h having a vertical forward surface 7' and a sloping rear surface k. The selector lever Ifi is similar to the selector lever it with the exception that the lever lt is a right-hand lever, while the lever l6 is a left-hand lever. The cam followers e of both levers and 66 ride in a camway 12 formed on the bottom of the casing 12.

The selector lever I6 is pivotally attached to a floating lever ll adjacent one end of the lever Il by means of a pin lB which is mounted in 55 Disposed in the guideway 20 at one end of the; guideway is a'roller stop 24* which cooperates with the lugs f andg of the lever lli and the selector' lever Iii is similarly pivotally attached to a floatinglever M The two floating levers I'I and ll are each slidably mounted at the ends nearest the pinsl8 in a channel-shaped guideway I9 (see Fig.4) which extends longitudinally of the casing I 2 at the right-hand side of the casing, as viewed in 'Fig. 4, whilethe other ends-of the floating levers are each slidably mounted in a channelshaped guideway' 20 formed in the head rod 4.

the adjacent end of the floating lever I 'l in a manner which will be described hereinafter, and

disposed in the guideway 20 at the other end'of' to. Referring particularly to the toggle mecha nism for operatively connecting the lever il with the casing l2, this mechanism comprises three links 21 '28 'and 29 and a latch 30 The links 27* and 28 are each pivotally attached at one end to the floatinglever Ha near the center of the lever by means of a pivot pin 3P, while the link 28 is pivotally attached at one end, by means ofa pivotv pin 32*, to the free ends of the links 21 and 28 and at the other end to the casing l2 by means of a pivot pint?) mounted in a pair of spaced lugs 34% The latch 30 is pivotal 1y mounted on the. pivot pin 33 above the link 25 and is provided adjacent its free end with a The recess 35 cooperates with a latch r'eoessSS. catch 36, provided on the link 21, in such man: her that when the links 2%, 28 and 29 are moved to substantially their dead center positions, the latch catch will enter the recess '35 and Will'thus hold the links in substantially their dead. center positions until the latch is subsequently released by timing mechanism which I will describe hereinafter. The latch is constantly biased to its 'latching 'positionwith respect to V the link 2% by means-of a compressed coil spring "37% one end of which is disposed in' a spring socket '38 formed in the side ofthe lever 29*, and the other end of which engages a depending .iug 39* which is formed on the latch 30 Since, as

; floating lever l 1? with the casing, it is believed; that the construction of this latter mechanism' was pointed out above, the toggle mechanism for "opjerativeiy connecting the floating lever, I'l with the casing I Zissimilarto that for connecting the will be apparentfrom an inspection of the drawings and from the foregoing description without further detailed description. 7

The biasing mechanismC also includes a spring 7 f 'unit U. This unit is mounted in a longitudinally extending semicircular depression 12 which is i'formed in the bottom ofthe casing l2 adjacent theleft-hand side. of the casing, as viewed in Fig. 4, and in the form here shown, comprises two I telescopically related tubular members 4 I and 42 provided at theiropposite ends" with end plates; 43 and 44. These end plates .are each'formed' 'with an axially disposed holethrough which a rod 45 passes with some a clearance.

The outer ends of the rod 45 are threaded-to receive'stop nuts ant-147, and surrounding the rodwithi-n the tubular members are two concentric compressed coil springs 52 and 53 which constantlybiasthe tubular members to the relative positions in which the end plates 43 and-44, respectively, engage the associated nuts 46 and 41. Formed integral'with the end plates 43 and 44, respectively, at the side nearest the floating levers are members 48 and 48* which extend parallel tothe associated tubular members, and provided on the tree ends of the members 48 and 48 are laterally projecting arms 5l and 5|, respectively; As shown in Figs. 3' and 6, the arm 5P is connected near 'its outer end by means of an upstanding web 50*,

with a similar arm 49 whichextends parallel to V the arm 5|, and the arm 5l is similarly con,-

nected near its outer end by means of an upstanding web 5ll with an arm 49* which is similar to, and which extends parallel to, the arm 5|. The leit-handends of the arms 49 and 5|, and 49 and Bi slidably, cooperate with the opposite sides of the head rod 4, and the right-hand ends of these arms slidably cooperate with'the outer faces of the members which form the guide way iii, in such manner that these arms are con-.

strained to slide'in a predetermined horizontal plane in the casing I2.

25 The left-hand sides of the arms 49 and fil and the right-hand sides 7 of the arms 43? and 5l as viewed in Fig. 5, are

curved as shown, for a purpose which will be. 30

madeclear presently. p r

A'roller assemblyR (see Fig. 10) comprising a roller journaled on a'pin 56 between two spaced circular members 5'! and 58 which are 7 rivetedto the pin 56*; iss'upported between the right-hand side ofthe floating lever I1? andthe left-hand sides of the arms 49* and 5I 'of the' spring unit U,-as viewed in Fig. 1, in such manner that the spring unit U acts through the roller assembly to constantly exert a biasing force on the floating lever, but that the roller assem-' bly can roll along the floating lever'from a point on oneside ofthe pivot pin 3l tola point on.

the other'side of this pivot pin, and thus change I the location at which the biasing force is applied to the lever} In a similar manner, a roller asi sembly R similar to the roller assembly R, is supported between the left-hand side of the floa.t.

ing lever H and the right-hand sides of the" arms 49 and 5| of the spring unit U, as viewed in Fig. Linsuch manner that'the spring unit U acts through this latter roller assembly to con stantly exert a biasing force on the floating lever,

but that, this latter roller assembly can roll along the floating lever l'l irom a' pointon one side of. the pivot pin 31'? to a point on the-other'side of this pivot pin, and thuschange the location at which the biasing force is applied to the floating lever li The roller assembly R is held in the proper vertical position relative to the arms 49 -and {Miami the floating lever 11, by

means of annular flanges 59 and 60 formed on the end. members 5! and 58 which flanges have larger diameters than the roller 55 andv are so proportioned that they will just clear the opposite sides of the floating lever and will also fit between the two arms 49 and 5| a with a small amount of clearance. "The roller assembly R is similarly-held in the proper vertical position '7 relative to the arms149 and '5l The parts are 'sofproportioned that when no train is trailing. the switch the roller assemblies R, and R will engage the floating leversf-l-l under these conditions, the spring unit U will and H in the relative positionsin which theyare shown engaging these levers in Fig. 2, and. that,

act through the roller assemblies R and R to bias the associated floating l'evers Fl and I! toward the'respective positions in which the selector lever l6 engages a boss 89* cast on the one end wall of the casing l2, and in which the selector lever l6 engages a boss 99 cast on the other end wall of the casing I2.

The timing mechanism referred to hereinbefore for releasing the latch 30 after the links 21 28 and 29 have been moved to substantially their dead center positions includes a timing device T comprising a cylinder 65 formed in a casing 65 which is secured to the head rod 4 by means of bolts 66. The outer end of the cylinder 64 is closed by a cylinder head 66*, and extending into the cylinder through a stuffing box 68 and through a hole 69 provided in the cylinder head is a piston rod Ili the inner end of which is secured to a reciprocable piston H The cylinder 65 is adapted to be filled with a suitable fluid, such as oil, and loosely mounted on a portion 12 of reduced diameter formed on the right-hand end of the piston H is an annular flapper valve l3 which, when the piston II is moved outwardly in the cylinder, opens and permits fluid to flow freely through a plurality of holes l4 that extend through the piston, but which, when the piston ll is moved inwardly in the cylinder, closes and prevents the:

flow of fluid through the holes 14*. The opposite ends of the cylinder are connected by a port 15 a passageway 16*, and a port Il An adjustable needle valve H3 extends into the port Hi and cooperates therewith to control the rate at which fluid can flow through the port 15*, the passageway 16*, and the port ll from one end of the cylinder to the other. The piston H is constantly biased to the inner end of the cylinder by a spring 19*, one end of which is disposed in a suitable socket 86 formed in the cas ing 12, and the other end of which engages an annular spring support 8 l which is secured to the outer end of the piston rod m The timing mechanism for releasing the latch 3|! after the links 21 28 and 29* have been moved to substantially their dead center positions also comprises a trip lever 82 which is pivoted intermediate its ends on a pivot pin 83 which projects downwardly from the under side of the head rod 4, and which, as shown in Fig. 4, is provided at its lower end with an enlarged head 84 One end of the trip lever 82 is provided with bifurcations 85 whichstraddle the piston rod Ill and which cooperate with the spring support 8| on the side opposite to that which is engaged by the spring w in such manner that the trip lever is biased to the position in which a stop 86* provided on the trip lever engages a vertical portion 8! of the head rod 4. The end portion of the trip iever opposite to the bifurcations 85 slopes downwardly a slight amount and cooperates with the lug h on the selector lever Hi and also with a lug B9 on the latch 36 of the trip mechanism. For reasons which will be made clear hereinafter, it is desirable that the trip lever should normally occupy the vertical position in which the end which cooperates with the lug h will be in a position to be engaged by the straight side 7' of the lug, but that, the lever may at times rotate slightly in a vertical direction about the piston rod Ill as an axis to a position in which the end which cooperates with the lug It will clear the lug, and in order to permit this action of the lever, the distance between the head 84* of the pivot pin 83 and the under side of the head rod 4 is made longer than the vertical thickness of the trip lever 82 and the trip lever is biased by its own weight and by a spring 88 to the vertical position in which the lever engages the head 34 of the pin 83*.

With the timing mechanism for tripping the latch 3W constructed in the manner just described, it will be apparent that if the trip arm 82 is rotated in a counter-clockwise direction in a horizontal plane about pin 83 as an axis, the piston H will be moved outwardly in the cylinder 65 and the spring Fil -will become compressed, so that if the force which rotated the lever in the counter-clockwise direction is then removed, the spring is will tend to restore the piston H and the trip lever 32 to their original positions. It will also be apparent that during the outward movement of the piston i l the flapper Valve 13 will open and permit fluid to flow freely through the holes W in the piston H but that, as soon as the spring 19 starts to restore the parts to their original positions, the flapper valve 73 will close, and the piston l! will then be constrained to move at the relatively slow rate at which fluid can flow through the port l5 past the needle valve 718 which rate can be controlled by adjusting the needle valve. It follows that when the parts of the timing mechanism have been moved away from their normal positions by the trip arm in the manner just described, the parts will not be restored to their full normal positions for a relatively long adjustable time interval.

The latch Ss of the toggle mechanism which operatively connects the floating lever H with the casing l2 has associated therewith timing mechanism for releasing this latch after the toggle levers 21 28 and 29 have'been mcved to their dead center positions, which latter mechanism is similar to that just described, and the parts of which are designated by the same reference characters as the corresponding parts of that just described, but with the distinguishing exponent b added thereto. Since the timing mechanism for releasing the latch 39 is similar to that for releasing the latch 39 it is believed to be unnecessary to describe this latter mechanism in detail. 7

The operation of the apparatus as a whole is as follows: When the movable rails 2 and 2 of the switch A occupy their normal positions in which they are shown in Fig. l. and the hand-throw lever ll of the switch operating device B is rotated to itsnormal position in which it is shown in Fig. 1, the parts of the biasing mechanism C occupy the positions in which they are shown in Fig. 2. That is to say. the pistons H and H of the timing devices T and T are held at the inner ends of their strokes by the springs 19 and 19*, the trip levers 82 and 82* are held in the positions in which the associated stops 8'5 and 85 engage the vertical ortions 81 andB'I respectively, of the head rod 4, both toggle mechanisnis are held in their collapsed pos tions, the rollers B and R engage the associated floating levers ll and il adjacent the lower ends of these levers, and the floating lever FF is' held by the force which is exerted on this lever by the spring unit U in the position in which the selector lever lfi attached thereto engages the boss 99{o'n the casing l2, while the flcating lever l'l is moved. a short distance away from the position in which the selector lever Iii attached thereto engages the boss 99 by engagement of the leftengages the boss 99 on the casing I2, a force' 'is transmitted from the operating rod I4 through portion of the selector lever I69.

hand side of the notch Id in the operating rod I4 with the short leg 0 of the L-shaped lower With the parts of the biasing mechanism in the positions 'just described, due to the fact that the floating lever I'I is helda slight distance away from the position in which the associated selector lever II;

the roller assembly 1R, to the spring unit U, which force compresses. the springs 52 and '53 of this unitbeyond their initial compression'so that the spring unit is accordingly effective to bias the movable rails to their normal, positions, the biasing force being transmitted from the spring unit to the movable rails through the roller assembly R the floating lever I'I selector lever IE boss 99*, casing I2, and head rod 4.

I will now assume that the parts are in the positions just described, and that his desired to move the switch to its'reverse position. To do this, the hand lever II of the switch operating device B is rotated from the extreme position in which it is shown in Fig; 1, through an angle of substantially l80in a counter-clockwisedirection, to its opposite extreme position. This rota' tion of the hand lever I I will cause the" operating rod I4 to move toward the left, a's'viewed in Fig. 1, and as, soon as the operating rod starts to 7 move, the left-hand edge of the notch I4 in the operating rod will move out of engagement with the short leg 0 of the selector lever 16 thus per-- mitting the compressed coil prings 52 and 53 of the spring unit to expand and move the floating lever I'I to the position in which the selector lever I6 engages the boss 99 As the operating rod continues to move, the right-hand side of the notch M in the operating rod will engage the short leg 0 of the selector lever I6 and will thus cause this lever, and hence the floating lever I'I to'move toward the left with the'cperating rod." This movement of the floating lever, in.

turn,-wil1 exert a force cn-the roller assembly R which force is transmitted through the spring unit 'U to the roller assembly R and thence through the floating lever Il selector lever I5 1308899 casing I2 and head rod 4, to the movable rails 2 and 2 of the switch, thus causing the movable rails to move with the operating rod until the rails reach their full reverse positions. 'When 'this happens, further movement of the movable rails is prevented, but the parts are so proportioned that the operating rod will continue to' move for-a short distance, andas a result, the.

springs 52 and 53 of the spring unit Uwill again become compressed beyond their initial compression, and will thus cause thespring unit to bias the movable rails to their reverse positions in a manner similar to that in which the movable rails are biased to their normal positions when 7 the hand-throw lever H of the switch operating device 3 occupies its normal'position.

When the switch A has'been moved to its reverse I position in the manner just described, and it is desired to restore the switch to its normal position,

' the short leg 0 fully enters the notch Il 'roll along the fixed rail I and the movable rail 2, the movable rails will be forced toward theirre-J verse positions by the wheels, and since the operating rod I 4 is now held fixed by virtueof its connection with the switch operating device, B, the casing I2 of the biasing mechanism '6 willmove toward the left as viewed in Fig. 2, relative to the operating rod. As the casing I2 moves toward the left, the selector lever I6, floating lever Ill, and

' associated parts will remain in the same relative positions withrespect to thecasing I2 in' which they are shown in Fig. 2. .The selector lever I6,

casing due tothe-engagement OfthB left-hand side of the notch Ila in the operating rod I4 with the short leg 0 of the selector lever; and as a 'result, as the casing moves relative to this lever, the camway I2 will cooperate with the cam follower e on the selector lever to move the right hand and of the selector lever, asviewed in Fig. 2, toward the operating rod to a positionin which thermore, as the casing I2 moves toward'the left relative ,to the selector'lever I6 a force will be exerted on the toggle links 21, 28 and 29 through the mediumof the lugs 34 and the pin 33%, which force, due to the fact that the floating lever I'I issecured togthe selector lever IS by means of thepin I8 and that the roller assembly,

R. isbiased into engagement with the lower end of the floating lever by the spring unit U, will cause the toggle 1inks'2l 28 and 29 to move to Fur ' however,.will beprevented from moving-with the 7 Q their dead centerpositi'ons and become latched in these positions, thus limitingfurthermovement of the pivot pin' 3| relative tothe casing I2 to rotation through an arc whose radius is equal to i the distance from the center of the pin 3 I to the center of the pin 33*. The casing I2 willcontinue to move toward the left after the toggle'links have become latched in theirdead center position's, and it will be apparent that this latter movement of thecasing willcause' a c'oupleto be exertedon the floating lever through the medium of the toggle links and the pivot pin IB,

which couple willcause the floating lever to rotate in a counter-clockwise direction about the pivot pinla During the first part of this rotation of the floating lever I'I" the roller assembly R, will be held in substantially the relative position in which it is shown in Fig. 2, but the roller assembly'R will be constrained to move with the casing. As a result, the springs -52'and 53 of the spring unit U will become compressed a considerable amount beyond their initial compression,

and as the floating lever I1? continues to rotate,

it will finally reach a position ill'WhlCh the surface against which'the'rollerassemblyR bears will slope upwardly toward the leftr instead of downwardly toward the left, as viewed in Fig. 2. When this happens, the roller assembly R, will move, due to the force which is'eicerted on it by thespring' unit U, from the relative position with respect to the lever IT, in which it 'is shown 'in Fig. 2, to the relative position in which it shown in'Fig. 1 1. As soon asthe roller moves past the pivot pin 3 I, the biasing force exertedby the spring unit U, which force was previously effectivelto bias themovable'rails to their normal positions, will then become effective to bias the movable rails to their reversef positions, thus causing the movable railstoicom plete their movement toward their reverse positions very'quickly. The reason why the biasing force changes its effective direction in the man'- ner just described is that as long-as the .roller assembly R engages the floating lever at a point below the pivot pin 3%, the force exerted by the biasing unit is transmitted to the movable rails in the manner previously described, but that, as soon as the roller R, moves above the pivot pin 3W, the floating lever I! then b comes a second-class lever whose fulcrum is the pivot pin 18 whose power arm is the portion between the point where the roller R, engages the lever and the axis of the pivot pin, and whose load arm is the portion between the axis of the pins 3N and w and the parts are so proportioned that under these conditions the resultant force which is then transmitted to the casing l2, and hence to the movable rails, will be in the opposite direction from that which was previously transmitted to the movable rails. The parts are further so proportioned that the floating lever ll will rotate to the position in which it becomes a second-class lever when the movable rails have been moved away from their normal positions a distance which is less than the smallest distance they would ever be moved by a train trailing the switch, and it follows that the movable rails will always become biased toward their reverse positions while a train is trailing the switch. The movement of the casing I2 toward the left relative to the operating rod also causes the left-hand side of the lower end of the trip lever 82 to engage the straight side :i of the lug h on the selector lever IE in such manner that the trip lever will be rotated in a counter-clockwise direction until the trip lever reaches the extreme position in which it is shown in Fig. 11, at which time the selector lever 18*, due to the previously described rotation of this lever caused by the cooperation of the cam follower c with the camway I22), will have been rotated to a position in which the lug it will move completely out of engagement with the trip lever. This counter-clockwise rotation of the trip lever will, of course, cause spring 19 to become compressed, and piston 1| of timing device T to be moved to the outer end of the cylinder 65 and as a result, as soon as the lug h clears the trip lever, the springs l9 will start to return the trip lever toward its original position at a rate which is controlled by the adjustment of the needle valve 18 in the previously described manner. When the trip lever has been returned to the position in which it is shown in dotted lines in Fig. 11, the trip lever will move into engagement with the lug 89 on the latch 33 and as the trip lever continues its movement it will exert a force on the latch which will finally trip the latch, and which will also cause the toggle links 21 28 and 29 to move away from their latched positions. As soon as the toggle links move away from their latched positions the pivot pin 3W will be free to move toward the left, and the force exerted on the floating lever by the spring unit will then cause the upper end of the floating lever to move into engagement with the roller stop 24 This movement of the floating lever Will change the floating lever from a secondclass lever to a third-class lever whose fulcrum and power arms will be the same as when it was a second-class lever, but whose load arm will now be the portion between the point at which the roller 24 engages the lever and the axis of the pivot pin 3l and the parts are so proportioned that under these conditions the resultant force which is transmitted to the casing 82 by the biasing unit will now be in a direction to cause the movable rails to move toward their normal positions. The parts of the timing mechanism will usually be so adjusted that the trip lever will not be returned to the position in which it trips the latch until a predetermined time interval has elapsed which time interval is of surficient duration to permit the trailing train when moving at a speed which is equal to or greater than a predetermined minimum speed to' have completely passed the switch, and it will be apparent, therefore, that when the biasing force again becomes effective to bias the movable rails to their normal positions, these rails will usually immediately start to return to their normal positions. Until the rails have been returned to within a relatively short distance of their normal positions the camway i2 will cooperate with the cam e on the selector lever it to hold this lever in the position in which the short leg 0 is within the notch M in the operating rod l4, and as long as the short leg 0 is within the notch E l the pivot pin I8 will be held in a fixed position relative to the trackway. The movement of the rails toward their normal positions will therefore cause the floating lever to rotate in a clockwise direction about the pivot pin W, and as the lever rotates it will finally reach a position in which the surface against which the roller assembly R bears will become inclined downwardly toward the left instead of upwardly toward the left. As soon as the floating lever reaches this position, the force which is exerted on the roller assembly by the spring unit will cause the roller assembly to move from the position in which it engages the floating lever adjacent its upper end to the position in which it engages the lever adjacent its lower end, and when this happens, the spring unit will then become efiective to bias the movable rails to their normal positions through the medium of the roller assembly R floatinglever ll selector lever I6", boss e9 casing l2, and head rod 4, thus causing a rapid return of the movable rails to their normal positions. The return movement of the rails will also cause the lower end of the trip lever 82 to move into engagement with the sloping surface is of the lug.

h on the selector lever, and since the trip lever is free to rotate in a vertical plane through a limited distance about the piston rod lil as a fulcrum, the lower end of the lever will slide over the lug, whereupon it will return to the position to which it is biased by its own weight and by the bias of the spring Bil Due to the relatively slow movement of the timing device T the timing mechanism may not be restored to its full normal position as soon as the rails have been restored to their full normal position, but when the timing mechanism has been restored to its normal position and the rails have reached their normal positions, all parts will then be restored to their normal positions in which they are shown in the drawings.

It should be pointed out that if under the conditions just described the timing mechanism including the timing device T had been set to re lease the latch at the expiration of ashorter time interval than that required for the train to trail the switch, the first pair of wheels that passed through the switch after the timing device had tripped the latch would ordinarily again condition the apparatus so that the switch would become biasedrto its trailed position for another time interval equal to that for which the timing mechanism is adjusted.

When the switch has been moved to its reverse position by the switch operating device B and a train trails the switch, the operation of the ap paratus is similar to that just described with the exception that under these conditions the floating lever I1 and associated parts at the right-hand end of the biasing mechanism C would become operative. Inasmuch as this operation is similar to that just described it is believed thatit will be fully understood from the foregoing description and from an inspection of the drawings without further description. 7

It will be seen that I have provided operating apparatus for a switch of the type which is adapted to be trailed, whereby the switch is nor.- mally biased to an extreme position corresponding to the position of the switch operating device B,.but that, when a train trails the switch, the switch then becomes biased to the position opposite to that corresponding to the position of the'operating device for a measured time'interval, and that when this time interval has expired, the switch again becomes biased to its original position.

One advantage of apparatus embodying my in- 'ous changes and modifications, may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a railway switch the movable rails of which are connected together by a head .rod, a biasing mechanism comprising a casing secured to said head rod, an operating device associated with said switch, an operating rod slidably mounted in said casing andoperatively connected with said operating device, a'floating lever slidably supported in said casing and operatively connected intermediate its ends with said c-as.

ing by means :of toggle mechanism including a latch for latching said toggle mechanism in substantially its dead center position when said toggle mechanism is moved to such position, means for operatively connecting said floating lever with said operating rod in such manner that when said operating device occupies one extreme position and said switch occupies a corresponding extreme position said toggle mechanism will be collapsed and said lever will be ro tated to one extreme position but that whensaid operating device occupies said one extreme position and said switch is moved away from the extreme position corresponding to the position of said device said toggle mechanism will be moved'to its latched position and said floating lever will be rotated to another extreme position, a spring unit, a roller assembly biased into engagement with said floating lever on the side opposite to said toggle mechanism by said spring according as said lever is rotated to its one extreme position or its other extreme position,

= timing mechanism set into operation when said toggle mechanism is moved to its latched posifrom its latched position bys-aid timing mecha:

nism, the parts being so proportioned that when I said toggle mechanismis collapsed and said lever is rotated to said one extreme positionsaid spring unit will bias said switch to the extreme position corresponding to the extreme position of said de vice butthat when said toggle'mechanism occupies its latched position and said lever is ro-.

tated to its other position said spring unit will then be effective to bias said switch to the extreme position opposite to that corresponding to said one extreme position of said device, and that after said toggle mechanism is movedfaway from its latched position said lever willthen'cooperate with said stop in such manner that said spring unit will again become effective to bias said switch to the extreme position corresponding to said one extreme position of said device. I 2. In combination," a railway switch movable between two extreme positions, means for normally biasing said switch to a: selected extreme position rneans effective when: said switchis moved away from said selected extreme position.

by a trailing train for biasing said switch to its opposite extreme position, and timing means set into operation when said second mentioned biasing means is actuated for terminating the effect of said second mentioned biasing means and for restoring the eiTect of said first mentionedbiasing means at the expiration of a measured time interval.

In combination, a railway switch movable between two extreme positions, means for normally biasing said switch to a selected extreme positicn, means eiiective when said switch; is moved away from said selected extreme position by a trailing train for biasing said switch toits opposite extreme position, and timing means-set into operation when said second mentioned" bias ing means is actuated for terminating the efiect of said second mentioned biasing means and for restoring the effect of said first mentioned biasing means at the expiration of a measured time interval which is sufficiently long to permit the train to completely trail the switch provided the train remains in motion at a speed which is equal to or greater than a predetermined minimum speed. I

4. In combination with a railway switch and an operating device movable between two positions to actuate the switch to corresponding positions, a spring unit connected with the switch and the operating device and normally effective to urge the switch to a position corresponding to the operating device, means responsive to the trailing movement of a vehicle wheel through the switch to cause said'spring unit to urge the switch to a position of disagreement with said device, and means set into operation when said first mentioned means is actuated for terminating the operation of said first mentioned means at the expiration of a measured time interval.

5. In combination with a railway switch and 7 an operating device movable between two positions to actuate the switch to corresponding positions, biasing .mechanism' connected with the switch and the operating device and normally effective to urge the switch to a position corre sponding to the operating device, means included in said biasing mechanism and efiective when .a

train trails the switch to cause the biasing mechanism to urge the switch to a position of dis agreement with said device, and timing means included in said biasing mechanism and set into operation whenever said first mentioned means is actuated for terminating the operation of said first mentioned means at the expiration of an adjustable time interval.

6. In combination with a railway switch and an operating device movable between two posi tions to actuate the switch to corresponding positions, biasing mechanism connected with the switch and the operating device and normally eifective to urge the switch to a position corresponding to the operating device, means included in said biasing mechanism and efiective when a train trails the switch to cause the biasing mechanism to urge the switch to a position of disagreement with said device, and timing means included in said biasing mechanism and set into operation whenever said first mentioned means is actuated for terminating the operation of said first mentioned means at the expiration of a time interval which is sufficiently long to permit the train to completely trail the switch provided the train remains in motion at a speed which is equal to or greater than a predetermined minimum speed.

'7. In combination with a railway switch and an operating device movable between two positions to actuate the switch to corresponding positions, a biasing mechanism comprising a casing secured to the movable rails of said switch to move therewith, an operating rod slidably mounted in said casing and operatively connected with said operating device, a spring unit in said casing, means in said casing for operatively connecting said spring unit with said operating rod in such manner that said spring unit is normally effective to bias the switch to a position corresponding to the operating device, means effective when a train trails the switch for modifying the connection between said spring unit and said operating rod in such manner that said spring unit is then eirective to bias the switch to a position of disagreement with the operating device, and means set into operation when said second mentioned means is actuated for terminating the eiiect of said second mentioned means and for restoring the efiect of said first mentioned means at the expiration of a measured time interval.

8. In combination with a railway switch the movable rails of which are connected together by a head rod, a casing secured to said head rod to move with the movable rails, a switch operating device, an operating rod slidably mounted in said casing and operatively connected with said operating device, a floating lever slidably mounted in said casing, means in said casing including toggle mechanism for operatively connecting said lever with said casing, other means in said casing for operatively connecting said lever with said head rod when a train trails the switch, the parts being so proportioned that when said operating device occupies one extreme position and said switch occupies a corresponding extreme position said toggle mechanism will be collapsed and said lever will be rotated to one extreme position but that when said operating device occupies said one extreme position andsaid switch is moved away from the corresponding extreme position said toggle mechanism will be moved to its dead;

center position and said floating lever will be rotated to another extreme position, latch mechanism effective when said toggle mechanism is moved toits dead center position for latching it in its dead center position, a spring unit in said casing operatively connected with said lever and said casing in such manner that when said device occupies its one extreme position said switch will be biased to its one extreme position or its other extreme position by said spring unit according as said lever occupies its one extreme position or its other extreme position, and timing mechanism in said casing set into operation when said toggle mechanism is moved to its dead center position and effective at the expiration of a predetermined time interval for tripping said latch mechanism and moving said toggle mechanism away from its dead center position.

9. In combination with a railway switch the movable rails of which are connected together by a head rod, a casing secured to said head rod to move with the movable rails, a switch operatingdevice, an operating rod slidably mounted in said casing and operatively connected with said operating device, a floating lever slidably mounted in said casing, means in said casing including toggle mechanism for operatively connecting said lever with said casing, other means in said casing for operatively connecting said lever with said head rod when a train trails the switch, the parts being so proportioned that when said operating device occupies one extreme position and said switch occupies a corresponding extreme position said toggle mechanism will be collapsed and said lever will be rotated to one extreme position but that when said operating device occupies said one extreme position and said switch is moved away from the corresponding extreme position said toggle mechanism will be moved to its dead center position and said floating lever will be rotated to another extreme position, latch mechanism effective when said toggle mechanism is moved to its dead center position for latching it in its dead center position, a spring unit in said casing operatively connected with said lever and said casing in such manner that when said device occupies its one extreme position said switch will be biased to its one extreme position or its other extreme position by said spring unit according as said lever occupies its one extreme position or its other extreme position, and timing mechanism in said casing set into operation when said toggle mechanism is moved to its dead center position and effective at the expiration of a predetermined time interval which is sufiiciently long to permit the train to completely trail the switch provided the train remains in motion at a speed which is equal to or greater than a predetermined minimum speed for tripping said latch mechanism and moving said toggle mechanism away from its dead center position.

KENNETH J. J. MCGOWAN. 

